In recent years several studies regarding possible effects of radio
frequency (RF) electromagnetic fields (EMFs) on cognitive brain function
were reported. In many of these studies on awake humans the working tasks
were presented visually to the test subjects, e.g., on a computer screen.
Therefore, the question of where in the chain of visual perception, brain
processing and response a possible effect could be induced seems to be of
interest.

Each test subject underwent
a battery of four different clinical tests three times (two different
exposure levels and sham exposure) to assess selected parameters of visual
perception. The generic signals applied to the subjects' head represented
the RF emissions of an UMTS mobile phone under constant receiving conditions
and the under condition of strongly varying transmit power, i.e., the signal
envelope contained low frequency components. In the high exposure condition
the resulting average exposure of the test subjects in the cortex of the
left temporal lobe of the brain was 0.63 W/kg (1 g averaged SAR) and 0.37
W/kg (10 g averaged SAR). Low exposure condition was one tenth of high
exposure and sham was at least 50 dB (corresponding to a factor of 100 000)
below low exposure.

Statistical evaluation of the obtained test results
revealed no statistically significant differences in the investigated
parameters of visual perception between the exposure conditions and sham
exposure.